Boiler



L. E. STEAR Jan. 3, 1933.

BOILER 1929 2 Sheets-Sheet Filed Feb. 19

Jan. 3, 1933. 1 E, STEAR 1,892,908

BOILER Filed Feb. 19, 1929 2 Sheets-Sheet 2 hwmfor Lawrence l 51cm* XVM a! Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE LAWRENCE E. STEAR, OF DETROIT, MICHIGAN, ASSIGNOR T NORMAN L. UPPER, 0F

DETROIT, MICHIGAN BOILER "Application mea February 19, 1929. serial No. 341,084.

This invention relates to a boiler adapted `for heating water or generating steam and is particularly concerned with a novel organization of parts whereby the heat supplied by .burning fuel is absorbed by the Water to a maximum degree withV the escape of a comparatively small portion of the heat through a stack or smoke pipe of the boiler.V

My inventionconsists in novel combina- 1`0 tions and arrangementsof parts for most effectively causing the absorption of heat from the burning fuel by the water contained in the boiler; A further object and purpose of the invention is to provide a boil-er containing a plurality of heating coils `of a special design so'mounted in flues through which the products of combustion pass that a greater absorption of heat is attained than heretofore. Coupled with the construction is a further construction and organization of the boiler whereby the heat, after it has passed by said coils, is further directed to circulate around the boiler andy supply heat thereto. A still furtherV 'object and purpose of the invention is to provide coils which-are very easily cleaned so that their outer surfaces can be maintained in proper condition to absorb and pass the heat to the water and not be insulated against heat absorption by collections of soot or the like on said coils. And a 'still further object of the invention is to provide a structure of' boiler whereby the coils are easily accessiblel either for cleaning or removal or replacement in the boiler, making it relatively simple and easy to always maintainV the boiler in perfect condition.

An understanding 'of the invention for 'the attainment of the ends described, as Well as 4o many others not at this time specifically stated, will be apparent'from the followingJ description taken in connection with the accompanying drawings, in which, y

F ig. l is afront elevation of the boiler. Y

i5 Fig. 2 is a horizontal sectionthroughthe boiler substantially on the plane of line 2-2 of Fig. 3. f

Fig. 3 is a vertical section substantially on the planev of line 3 3 of Fig. 1.

F ig; 4 is a horizontal section on the plane "7 of line 1 4 of Fig. 3, and

Fig. 5 is a fragmentary perspective view lof the' upper end portionof one of the coils, a plurality of. which are used in the construction kof the boiler.

, Like reference characters referto like parts in the' different figures of the drawings.

' In. the construction, a lower shell 1 of metal is provided which is lined with suitable heat resistance material 2 forming a combustion chamber for the fuel which is to be burned under the boiler. A door 3 for the entrance into said chamber is provided at the front in the usual manner. The shell l at its upper edge is formed with integral circular ledges 4. and 5, the ledge 4 extending inwardly from the shell l and the ledge 5 extending outwardly therefrom.' Said ledges are located substantially in a horizontal plane. On these ledges the boiler construction of my invention is designed to be mounted.V

f VThe boiler includes in its construction a bottom plate 6 preferably of circular form having an annular continuous vertical flange 7 at its outer edges over which a drum 8 of metal is positioned, the flange 7 and drum 8 being Vwelded or otherwise permanently secured togetherV to provide a water and steam tightjointf At the upper end ofthe drum 8 a head is located having a top 9 with depending sides 10 and, as the stop 9 is larger in diam'eter than the diameter of the drum 8, horizontal sections ll extend inwardly from thef lower edges ofthe sides 10 to join with the upperend of the drum 8. It is, of course, to be understoodthat the connection of the boil- -er head to the drum is a very permanent and secure connection and one which 1s water and steam tight. The head 9 is of circular of larger' diameter except that at one side it is formed with an inward recess 12, best shown in Fig. 4, the purpose of which will later appear.

Surrounding the boiler construction described is an outer casing 13 of metal which rests at its lower edge upon the ledge 5, the boiler itself, which is to contain water to be heated, resting upon the inwardly extendingl ledge 4. rlhe casing 13 has an inner diameter equal to the outer diameter of the head of the boiler so that the upper end of the casing is completely illed by the boiler head except at the recessed portion 12, this providing a con necting flue for the space above the boiler and that between the drum 8 and casing 13 below the head of said boiler. At the upper end of the casing a closing head, having an upper horizontal top 14 with depending sides 15, is secured, the upper or top side 14 being spaced a distance above the upper side or top 9 ofthe boiler head.

At one side of the top closing member of the casing, a horizontal outlet 16 is provided with which a smoke pipe 17 is connected, provided with a damper 18 therein which may be manually moved to open or closed positions in the usual manner. The outlet 16 is at a point diametrically opposite the recessed or flue portion 12 of the boiler head. A second outlet pipe 19 for the products of combustion is connected at the lower end ofthe casing 13, extends outwardly for a short distance and is connected to the upper pipe 17 by vertical pipe 20, the connection of pipe 2O being back of the damper 18. The enclosing drum or casing 13 `and the coveringhead therefor is covered with an asbestos 21 for the purpose of preventing heat radiation.

In the upper side of the top 14 of the outeiI enclosing casing of the boiler a large opening is made nearly as large as the diameter of the drum 8 which is closed by a late 22 of the form shown, it likewise at its outer side being covered by asbestos or equivalent heat insulating material, as indicated at 23. The purpose of this large opening and cover will be later described.

A plurality of water carrying coils 24 are used with the boiler. These coils are of a spiral form and in cross section have upper and lower flat sides 25 located closely together, as shown in Fig. 5. At their ends the coils are formed into substantially tubular terminal sections 26 which may be connected by unions 27 with short pipes 28, in turn secured to and extending through sides of vertical flues 29 located within the drum 8 between the bottom 6 and the upper side 9 of the boiler.

A plurality of the fines 29 are used, the number used being dependent upon the diameter of the boiler drum 8, and the same are 'welded or otherwise connected at their ends)` to the top and bottom of the boiler with the coils 24, previously described, connected at their lower ends with the tlues near the lower ends thereof and at their upper ends connected with the sides of the flues at a point below the normal water line of the boiler. The surface in the top 9 ofthe boiler head occupied by said liues is such that when the cover 22 is removed all of the flues are directly accessible from above through the opening left by removal of the cover, and by introducing a brush of proper form into a flue and by turning it about a vertical axis down through each coil all soot or other deposits on the sides of the coil may be very quickly and easily removed.

The boiler is supplied with water from any main supply through pipes 30 which preferably enter the lower end of the boiler at opposite sides thereof. Of course, one pipe only for supplying water could be used, but it is preferred to use at least two; and if more than two are used the same will be equally spaced from each other. The outlets for steam are indicated at 31 as extending upwardly from the top of the boiler head. Various clean-ont doors 32 are made at opposite sides of the enclosing casing, while the boiler is supplied with the usual pressure oauge 33 and water level indicating glass 34, all of which are not new but are accessories to practically all boilers.

llVhen fuel is burned in the combustion chamber below the boiler the hot products of combustion pass upwardly thru the flues 29 and circulate around the spiral coils 24 and pass therefrom to the space above the' boiler below the top plate 14 of the casing. llVith the damper 18 closed the products of combustion are directed to and passed downwardly through the flue formed at 12 and thence go in both directions around tl e outer side of the drum 8 to the outlet 19. 0f course, bv turningr the damper 18 to horizontal position the products of combustion can pass directly from the flues 29 into the outlet pipe 17. With this circulation of the products" of combustion and their intimate contact with the coils 24 and the inner sides of the tlues 29. and with the outer sides of the drum 8. the water within the boiler receives heat and that within the coils 24 is heated very rapidlv and circulates, the water'emptyiug at their upper ends into the boiler and being received at their lower ends from the boiler. The heat is absorbed very rapidly. so much so that the temperature of the products of combustion in the pipe 19 is very much below that usually found in the smoke pipes for boilers or furnaces. The particular shape of the coils 24 is a very important feature of the invention, not only lending itself to rapid heat absorption and rapid heating of water within the coils, but also being very quielrliv and easily cleaned and. kept in clean ondition. The removable cover 22 permits immediate access to the flues and the coils -J therein, both for cleaning and for repair or replacement of coils should they become injured or collect scale at the inner sides thereof, or for any other reason. The unions 27 are very easily reached and the coils can be disconnected and removed easily. The circulation of water through the coils is normally suiiiciently rapid that deposit of scale thereon is almost if not completely avoided'.

This boiler has been subjected to severe test and has proved to be one of exceptionally high eliiciency in diminishing losses of heat and in providing for the rapid production of steam. In fact, in proportion to the size of the boiler the production of steam is greatly in excess of any other boilers known to me having substantially the same size.

Many variations in the specitlc detail of the structure shown may be resorted to without departing in any way from the invention. All of such mechanical details of structure a casing surrounding the drum and head and supported at its lower end on said outwardly extending ledge, said casing at its upper end being spaced from the upper side of the head and at its inner side bearing against the outer sides in said head, said head being recessed to provide communication between the spaces above and below the head within the casing, and an outlet pipe for products of combustion connected with and leading from the lower end ot said casing opposite where said recessed portion of the head is located.

In testimony whereof I ailix my signature.

LAWRENCE E. STEAR.

may be varied in a great many ways. The

invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

l. A boiler comprising, a vertical drum, a head of larger cross sectional area attached to the upper end of said drum having a horizontal upper side, a plate closing the lower end of the drum, a plurality of vertical ilues disposed between the upper side ot the head and said bottom plate and secured at their ends thereto, a spiral coil located vertically in each flue and attached at its ends to the sides of the flue to communicate with the interior of said drum and head, a casing surrounding said drum and head, the inner dimension of the casing being substantially equal to the outer dimension of said head and said head at one point being inwardly recessed to provide communication between the space above said head and the space below the same around the drum, and an outlet pipe for products of combustion connected with and leading from the lower end of the casing at the side thereof substantially opposite where the recessed portion of the head is located.

2. A boiler construction comprising, a combustion chamber including a suitably lined shell, said shell at its upper end having inwardly and outwardly extending horizontal ledges, a vertical drum bearing at its lower end on the inwardly extending ledge, a plate closing the lower end of the drum, a head Y having a larger diameter than the drum secured to the upper end thereof, said head having a substantially horizontal upper side, a plurality of vertical lines disposed between the upper side of the head and said plateand permanently secured thereto within Vsaid drum and head, a spiral coil located vertically in each flue and connected at its opposite ends to and extending through the sides of the flue to communicate with the interior of the drum, 

